Focusing device for microscopes



July 11, 1939. R. D. ALLISON FOCUSING DEVICE FOR MICROSCOFES Filed May 3, 1937 myaM lZ;

ATTO RN EYS Patented July 11, 1939 UNITED STATES PATENT OFFICE FOCUSING DEVICE FOR IVIICROSCOPES Raymond D. Allison, Los Angeles, Calif.

Application May 3, 1937, Serial No. 140,533

7 Claims. (01. 88-39) This invention relates to focusing devices for adjustment pinion head, l6 the fine adjustment microscopes and has for an object to provide 'pinion head, l! the stage, it the objectives and means by which the focusing operation may be I9 the clamps for holding a slide 20 on the stage, quickly and safely accomplished without danger these parts being common to all microscopes.

of damaging the lenses of the objectives, slides The fine adjustment body is mounted for vertical 5 placed upon the stage of the microscope, conadjustment on the pillar arm, and the coarse denser, or iris diaphragm through forceful conadjustment body is mounted for vertical adjusttact with the objective due to improper manipument on the fine adjustment body while the fine lation of the focusing adjustments of the microadjustment body is disposed between the coarse l0 scope. adjustment body and the pillar arm. 10

A further object of the invention is to provide In practice, in bringing the instrument to foa device which will permit focusing of any objeccusing position by manipulation of the coarse tive in the normal manner but will stop the adjustment the body tube of the instrument downward action of both coarse and fine adjustmoves quit-e rapidly and the focusing point may ments at a point which will not permit the front be passed in which case further down movement 15 lens of the objective to contact with the object of e bo y tu by either Coarse fi j slide, the device being so constructed as not to m nts brin s the o j ctive into Contact with the interfere with any adjustment of the microscope slide or parts o the microscope below h Slide until its focusing terminus is reached and then resulting in eat that point the device renders both coarse and With. this objection in mind the invention profine adjustments inactive. vides a substantially straight bar 22 having a With the above and oth r objects i vi th downwardly directed foot 2| that is secured to invention consists of certain novel details of conthe real face of the o y u S e f c struction and combinations of parts hereinafter at the p thereof y a Screw 23 and P fully described and claimed, it being understood Passed into the tube Slide 50 that the bar moves t that various modifications may be resorted to as a u p and down W th he ube- The bar within the scope of the appended claims ith t extends from the coarse adjustment slide or rack departing from the spirit or sacrificing any of heroes the fi adjustment dy and a sc ew 24 the advantages f the inve ti is screw threadedly engaged with the freeend of 54,) In the accompanying drawing forming part of the bar and depends from the bar between the this specification, bar and the stationary pillar arm. The screw Figure l is a perspective view of a microscope is provided With a 100k nut 25 and also is p embodying one f rm of th in ti vided with an elongated knurled cylinder head 26.

Figure 2 is a side elevation of the device con- By tur i g the head 26 the screw m y be dstituting the subject matter of the invention with iust d vertically t project y d s r d dista e 35 associated parts of the microscope shown in from the bar 22 and locked in this adjusted p dotted lines. tion by tightening the nut 25. The purpose of Figure 3 is a front elevation f th device this vertical adjustment of the screw is to provide Figure 4 is a bottom plan view of the device. an adjustable Control O the free Working dis- Figure 5 is a detail side elevation of a modified tahee between the Objective and the O ject 40 form of the device, slide 20 by stopping movement of the bar at a Figure 6 is a detail side elevation of another predetermined point in its travel as a unit With modified f rm f th d vic the coarse adjustment slide or rack.

Figure '7 is a side elevation of still another In Operation W h body e is being modified form of the device. moved downward by means of either the coarse 45 Figure 8 is a detail side elevation of a modified fine adjustment the knurled head 6 0f the form of bar for supporting the motion limit screw Screw Wi 11 Strike against the Stationary p a shown in Figure 1. arm [3 outside of and beyond the fine adjustment Referring now to the drawing in which like body l4 immediately upo the y tube P s characters of reference designate similar parts the focusing DO AS a result t Obj t ve '8 50 in the various views, 9 indicates the draw tube, can never at any time be impinged against the ID the body tube, H the body tube slide, l2 the slide 20 or be advanced through the stage to body tube rack representing the coarse adjustinjure other parts of the microscope on the botment body, 13 the upper portion of the pillar tom of the stage.

arm, [4 the fine adjustment body, I 5 the coarse It will be pointed out that once the proper 55 .which is secure-d to the pillar arm.

adjustment of the screw 2 is made, it never again need be adjusted unless a different thickness object slide is used. Even when a diiferent magnification is desired, and a selected objective is rotated into focusing position on the nose piece of a parfocalized microscope the screw 26 prevents the objective striking against the object slide even when some manipulation of the fine adjustment is made, as in practice when the stop arm and screw is in use it will be found that the fine adjustment body instead of traveling lower to a dangerous position will begin to rise and thus prevention of breakage is assured at all times.

In Figures 5, 6 and 7 modified forms of stop arms and screws are shown, and in these figures the microscope is turned around to a position 180 from the position shown in Figure 1, that is, the body tube is on the left of each figure instead of on the right of the figure as shown in Figure 1.

The modification shown in Figure 5 comprises a bar 2'! which is adjustably mounted intermediate its ends by means of a pivot screw 23 threaded into the pillar arm 29. A stop pin 38 is secured to the side of the body tube slide or rack Si and is adapted to engage the end of the bar 2?! and stop dangerous movement of the body tube 32 toward the objective slide. The bar is provided with a segmental shaped end 33 having an arcuate slot 35 concentric with the pivot pin and receiving an adjusting screw 35 The screw 35 is loosened when the bar 2? is to be adjusted and as soon as the desired terminus of the body tube is ascertained the bar is rocked on the pivot screw 28 to a position where the bar contacts with the stop pin 38 and then the adjusting screw 35 is tightened to maintain the bar rigid in place in this adjusted position. The end of the bar may be graduated for convenience in making future adjustments and in all forms of the invention wherever desired scales for facilitating adjustments may be arranged wherever necessary.

Another modification of the invention is shown in Figure 6 in which a bar 36 is fixed to the bottom of the pillar arm 37 by screws 38 or other connectors. The free end of the bar is oiTset downwardly and is equipped with a screw 39 which extends upwardly in the path of movement of the body tube slide or rack 40 and is adjustably secured in place by a lock nut .1. The screw 39 engages the body tube slide or rack and prevents downward movement of the body tube 42 to a dangerous point below the focusing point.

Still another embodiment of the invention is shown in Figure '7 in which a bar 4-? is pivoted on a bracket M which is secured to the bottom of a pillar arm 45 by a screw 46 or other connector. One end of the bar is equipped with an upstanding pin t? which projects into the path of the body tube slide or rack Q8. The other end of the bar is equipped with a screw 49 having a shoulder 58 in contact with the top face of the bar 43 and also is provided with a shank of reduced size to extend through the bar 43. The end of the screw is further reduced to receive a knurled nut 5! adapted to engage the shank and permit the screw 39 to turn freely on the bar 43. The other end of the screw 49 engages in a threaded opening 52 formed in the underside of the pillar arm 45. A look nut 53 on the screw 49 is screwed up tight against the bottom of the pillar arm in order to lock the screw in adjusted position to maintain the upstanding pin in vertically adjusted position.

In all forms of the invention it will be noted that some means is provided on a part of the microscope moved by the coarse adjustment for engaging a stationary part of the microscope to prevent the adjustable part being moved downward to a dangerous point past the focusing point of the instrument. In all cases, a bar or other device is provided which extends across,

above, below, or through the fine adjustment body when making the contact between the stationary part and the coarse adjustment. The device in all instances stops the action of both the coarse and the fine adjustment at a predetermined point of travel toward the object slide.

In some instances it may not be necessary to equip the bar 22 shown in Figure 1 with a foot and accordingly, as best shown in Figure 8, the bar designated by the numeral 55 may be simply a straight bar adapted to fit on top of the body tube slide or rack 55 and to be secured thereto by a screw 56 and a pin 57. The bar is equipped with a motion limiting screw 53 similar to the like screw 24 shown in Figure 1 and having a knurled head 59. The screw is secured in adjusted positions on the bar by a lock nut 60.

From the above description it is thought that the construction and operation of the invention will be fully understood Without further explanation.

What is claimed is:

1. A microscope having a stationary pillar arm, a fine adjustment body mounted for vertical adjustment on the pillar arm, a coarse adjustment body mounted for vertical adjustment on the fine adjustment body, the fine adjustment body being disposed between the coarse adjustment body and the pillar arm, an objective, a stage for supporting an object slide, means providing an adjustable control of the free Working distance between the microscope objective and the object slide, comprising a bar extending from the coarse adjustment body across the fine adjustment body to the pillar arm, and an adjusting screw between said pillar arm and the bar adapted to stop movement of the bar at a predetermined point in its travel as a unit with the coarse adjustment body.

2. A microscope having a stationary pillar arm, a fine adjustment body mounted for vertical adjustment on the pillar arm, a coarse adjustment body mounted for vertical adjustment on the fine adjustment body, the fine adjustment body being disposed between the coarse adjustment body and the pillar arm, means carried as a unit by the coarse adjustment body and engageable with the stationary pillar arm to limit downward movement of the coarse adjustment body beyond a predetermined point past the focusing point, said means extending freely and transversely across the fine adjustment body.

3. A microscope having a stationary pillar arm, a fine adjustment body mounted for vertical adjustment on the pillar arm, a coarse adjustment body mounted for vertical adjustment on the fine adjustment body, the fine adjustment body being disposed between the coarse adjustment body and the pillar arm, an objective, a stage for supporting an object slide, an adjustable stop member extending from the coarse adjustment body across the fine adjustment body and adapted to engage the stationary pillar arm for providing an adjustable control of the free working distance between the microscope objective and the object slide.

4. A microscope having a stationary pillar arm, a fine adjustment body mounted for vertical adjustment on the pillar arm, a coarse adjustment body mounted for vertical adjustment on the fine adjustment body, the fine adjustment body being disposed between the coarse adjustment body and the pillar arm, a slide supporting stage, an objective, a bar extending from the coarse adjustment body across the fine adjustment body and overhanging the pillar arm, and a member carried by the bar forming a stop adapted to engage the pillar arm and prevent contact of the objective with an object slide.

5. A microscope having a stationary pillar arm, a fine adjustment body mounted for vertical adjustment on the pillar arm, a coarse adjustment body mounted for vertical adjustment on the fine adjustment body, the fine adjustment body being disposed between the coarse adjustment body and the pillar arm, a stage for supporting an object slide, an objective, a bar mounted between its ends on the pillar arm and extending across the fine adjustment body to the coarse adjustment body, a stop pin secured to the coarse adjustment body adapted to engage the end of the bar and hold the coarse adjustment body against movement toward the object slide, and means between the other end of the bar and the pillar arm for adjusting the free end of the bar vertically.

6. A microscope having a stationary pillar arm, a fine adjustment body mounted for vertical adjustment on the pillar arm, a coarse adjustment body mounted for vertical adjustment on the fine adjustment body, the fine adjustment body being disposed between the coarse adjustment body and the pillar arm, a slide supporting stage, an objective, a bar secured to the bottom of the pillar arm and extending across the fine adjustment body, the free end of said bar being offset, and a pin extending upwardly from the free end of said bar in the path of movement of the coarse adjustment body and adapted to engage the coarse adjustment body and prevent movement of the coarse adjustment body toward the slide supporting stage.

7. A microscope having a stationary member, a fine adjustment body mounted for vertical adjustment on the stationary member, a coarse adjustment member mounted for vertical ad.- justment on the fine adjustment body, the fine adjustment body being disposed between the coarse adjustment member and the stationary member, bar means attached to one of said members, the free end of said bar means bridging the fine adjustment body, and contact means coacting with the free end of the bar means and with the other of said members for stopping vertical movement of both the coarse adjustment member and the fine adjustment body at a predetermined point.

RAYMOND D. ALLISON. 

